From aa47e0b7d457f289dbb917fa63d37207aa6769e4 Mon Sep 17 00:00:00 2001 From: Ferruh Yigit Date: Tue, 20 Nov 2018 12:50:31 +0000 Subject: [PATCH] doc: announce disabling GCC AVX512F as known issue Document that AVX512F has been disabled for GCC builds [1] and document its potential implications on release notes, known issue section. [1] Commit 8d07c82b239f ("mk: disable gcc AVX512F support") Signed-off-by: Ferruh Yigit Acked-by: John McNamara --- doc/guides/rel_notes/release_18_11.rst | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/doc/guides/rel_notes/release_18_11.rst b/doc/guides/rel_notes/release_18_11.rst index f66ade2a52..0c91c75796 100644 --- a/doc/guides/rel_notes/release_18_11.rst +++ b/doc/guides/rel_notes/release_18_11.rst @@ -584,6 +584,17 @@ Known Issues * IBM Power8 is not supported by this release of DPDK. IBM Power9 is supported. +* ``AVX-512`` support has been disabled for ``GCC`` builds [1] because of a crash [2]. + This can affect ``native`` machine type build targets on the platforms that support + ``AVX512F`` like ``Intel Skylake`` processors, and can cause a possible performance drop. + The immediate workaround is to use ``clang`` compiler on these platforms. + Issue has been identified as a GCC defect and reported to GCC community [3]. Further + actions will be taken based on the GCC defect result. + + [1]: Commit 8d07c82b239f ("mk: disable gcc AVX512F support") + [2]: https://bugs.dpdk.org/show_bug.cgi?id=97 + [3]: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88096 + Tested Platforms ----------------